The present invention relates generally to agents for improving the quality of citrus fruits and to a method of improving the quality of citrus fruits by application of such agents.
Chemicals capable of adjusting the metabolism of sugars and/or organic acids of citrus fruits are very useful, because they can improve the quality of citrus fruits and adjust the shipping time of the fruit. Chemicals capable of performing this function such as lead arsenate and naphthylacetic acids, are known. Lead arsenate has a pronounced effect of decreasing acidity of citrus fruits. However, lead arsenate is harmful to fruit trees and is residual in the fruit. Therefore, this agent is not preferable in view of the safety factor. Naphthylacetic acids also decrease the acidity in citrus fruit; but delay maturity of the fruit. This creates a problem in scheduled shipping time of the fruit, thus proving to be of little practical use.
As a result of various studies, it has been found that certain compounds as set forth below can increase or decrease the amount of organic acids in citrus fruits, when applied to the fruit trees without doing any harm to the fruit trees or having any adverse effect upon the maturity of the fruit.